Bleeding the proportioning valve

[chrismoore701]

I am moving to the brakes on my 79 C10 Frame off. I have a new booster, master cylinder and proportioning valve. I have heard you need to bench bleed your master cylinder and bleed the proportioning valve. I assume I just fill the master cylinder up with fluid and compress the piston a few times, but how do you bleed the proportioning valve?

Thanks

[geezer#99]

You don't bleed the prop valve!
But you do need to depress and hold in the reset button on the front of the prop valve while you bleed the brakes.

[chrismoore701]

I have a plastic plug tool thing that came with it. Do I just screw this in while bleeding?

[geezer#99]

We need a pic!!

[motornut]

Originally Posted by chrismoore701

I have a plastic plug tool thing that came with it. Do I just screw this in while bleeding?

could be to keep dirt out during shipping?

[chrismoore701]

Here ya go
http://m.ebay.com/itm/CHEVY-GM-Propo...851?nav=SEARCH

I here you just screw it in while bleeding

[geezer#99]

With that style prop valve you do.
Keeps the piston centered so you have fluid front and back.

[craig113]

I copied the part from the article below. But the link to the whole article is http://www.classicperform.com/TechBo...t.htm#testprop It seems very good and covers alot of brake problems. I hope it works.

Test Combination/Proportioning Valve
Use a test light by attaching a clip to a positive contact on the vehicle and touch the point of the tester to the electrical connection of the combination valve. If the the light does not come on, the valve system is operating correctly and no further testing is required.
If the light does come on, this indicates that the pressure differential valve is stuck in the front or rear position.
Bleed the brake system to determine if the front or rear lines are blocked off. Set up one front wheel and one rear wheel for bleeding at the same time. Crack both bleeder screws and gently pump the pedal a few times.
The blocked side will trickle fluid out when the bleeder screw is cracked and the pedal pressed. An unblocked line will squirt fluid out the bleeder.
The lines that are clear must be left open and the blocked lines should have the bleeder screws tight to cause pressure to build up on that side. Be sure to use the standard bleeding procedures to prevent air from entering the system.
Slowly press the pedal with steady pressure a number of times until the light goes out; this will center the differential valve. You may also hear a pop come from the proportioning valve. This is the metering valve returning to its equalized position. When the light goes out, close the bleeder screw.

put a 2x4 under your brake pedal, to keep from over stroking you could get buy without the tool assist

[chrismoore701]

Thanks